Septic tank systems normally include a septic tank and a distribution system for expelling effluent from the septic tank through the distribution system into one or more absorption fields. A limiting condition on the effectiveness and capacity of the septic tank system is the absorption capacity of the absorption fields. When the amount of effluent exceeds the capacity of the absorption field saturation of the field and possible back-up of the septic tank results. This problem has forced may people to unnecessarily limit the size of their septic tanks and the amount of effluent expelled from septic tank.
In the past, the main methods used to increase the absorption capacity of a septic tank system was to add additional absorption fields and to provide a plurality of distribution outlets for directing the effluent to these different absorption fields. However, difficulty has been encountered in controlling the proportion of the total effluent directed to each absorption field. U.S. Pat. No. 3,497,067 disclosed a solution to this problem which includes a flow divider that equally divides the effluent between two absorption fields. In this system each absorption field receives approximately equal amounts of effluent. This solution is usually effective in preventing saturation. Nevertheless, in some instances one absorption field will become saturated before the other. Therefore, some type of control means is needed to direct effluent in any desired proportions to respective absorption fields.